Shaping infants' social brains through vicarious social learning: the importance of positive mother-father interactions

Introduction

This study is the first to assess whether infants' developing social brains may be susceptible to the vicarious social experience of interparental positivity. Specifically, we explored whether infants' exposure to interparental positivity may vicariously shape their neural substrates of social development.

Methods

In a sample of 45 infants (M AgeMonths = 11.01; 48.9% girls), infant left-frontal resting alpha electroencephalogram (EEG) asymmetry was derived as a reliable indicator of neural substrates linked to adaptive social development. Moreover, positive characteristics of the mother-father couple relationship were assessed both by means of observation and self-report by mother and father. Importantly, various relevant covariates were considered, including interparental negativity (observed and self-reported), as well as infants' direct caregiving experiences and duration of infant exposure to mother-father relationship-dynamics (parent-report).

Results

Results indicated that higher levels of observed interparental positivity were associated with greater infant left-frontal alpha EEG asymmetry, even after accounting for covariates (β's > 0.422).

Discussion

The current study's results are first to suggest that positive vicarious social experiences in infants' day-to-day lives play a significant role for early neural development.

Frontal alpha asymmetry in anxious school-aged children during completion of a threat identification task

Asymmetry of EEG alpha power in the frontal lobe has been extensively studied over the past 30 years as a potential marker of emotion and motivational state. However, most studies rely on time consuming manipulations in which participants are placed in anxiety-provoking situations. Relatively fewer studies have examined alpha asymmetry in response to briefly presented emotionally evocative stimuli. If alpha asymmetry can be evoked in those situations, it would open up greater methodological possibilities for examining task-driven changes in neural activation. Seventy-seven children, aged 8-12 years old (36 of whom were high anxious), completed three different threat identification tasks (faces, images, and words) while EEG signal was recorded. Alpha power was segmented and compared across trials in which participants viewed threatening vs. neutral stimuli. Threatening images and faces, but not words, induced lower right vs. left alpha power (greater right asymmetry) that was not present when viewing neutral images or faces. Mixed results are reported for the effect of anxiety symptomatology on asymmetry. In a similar manner to studies of state- and trait-level withdrawal in adults, frontal neural asymmetry can be induced in school-aged children using presentation of brief emotional stimuli.

Functional role of frontal electroencephalogram alpha asymmetry in the resting state in patients with depression: A review

Depression is a psychological disorder that affects the general public worldwide. It is particularly important to make an objective and accurate diagnosis of depression, and the measurement methods of brain activity have gradually received increasing attention. Resting electroencephalogram (EEG) alpha asymmetry in patients with depression shows changes in activation of the alpha frequency band of the left and right frontal cortices. In this paper, we review the findings of the relationship between frontal EEG alpha asymmetry in the resting state and depression. Based on worldwide studies, we found the following: (1) Compared with individuals without depression, those with depression showed greater right frontal EEG alpha asymmetry in the resting state. However, the pattern of frontal EEG alpha asymmetry in the resting state in depressive individuals seemed to disappear with age; (2) Compared with individuals without maternal depression, those with maternal depression showed greater right frontal EEG alpha asymmetry in the resting state, which indicated that genetic or experience-based influences have an impact on frontal EEG alpha asymmetry at rest; and (3) Frontal EEG alpha asymmetry in the resting state was stable, and little or no change occurred after antidepressant treatment. Finally, we concluded that the contrasting results may be due to differences in methodology, clinical characteristics, and participant characteristics.

Electroencephalographic Signature of Negative Self Perceptions in Medical Students

Frontal alpha asymmetry (fAA) is purported to be a neurophysiological marker for anxiety and depression. Higher left frontal alpha EEG voltage is associated with lower left and higher right frontal cerebral cortical activation, indicative of right-sided fAA. This pilot study tests the hypothesis that greater left-sided frontal alpha voltage is associated with negative thoughts about oneself. A group of eight healthy 28-41-year-old right-handed male medical students were subjected to an extensive interactive self-report inventory (ISI) evaluating perceptions of their psychosocial interactions. Quantitative EEG (qEEG) was performed with eyes closed. Computations of fAA and related parameters were based on measurements in the alpha bandwidth (8-13 Hz) at the left frontal F7 and right frontal F8 scalp electrodes. fAA was the percent difference between mean voltages at F8 minus that at F7. Significance of associations between fAA and the ISI scores was determined by Pearson’s product-moment correlation coefficient, at P≤0.05. “Depressed” scores were positively correlated with right-sided fAA (P=0.01). “Relaxed” (P=0.05), “regulated” (P=0.02), “cooperative” (P=0.05) and “dependent scores” (P=0.004) were negatively correlated with right-sided fAA. These findings imply that right-sided fAA may be associated with more perceptions of “depressed” psychosocial interactions involving negative thoughts about oneself, as well as, more reliance on others (“dependence” score), less sharing (“cooperative” ISI score), less trust (“regulated” ISI score) and less initiative (“relaxed” ISI score). These results support the hypothesis that right-sided fAA may identify individuals with a predilection for negative thoughts about themselves and other negatively-valenced perceptions of their psychosocial interactions.

Electroencephalography Correlates of Well-Being Using a Low-Cost Wearable System

Electroencephalography (EEG) alpha asymmetry is thought to reflect crucial brain processes underlying executive control, motivation, and affect. It has been widely used in psychopathology and, more recently, in novel neuromodulation studies. However, inconsistencies remain in the field due to the lack of consensus in methodological approaches employed and the recurrent use of small samples. Wearable technologies ease the collection of large and diversified EEG datasets that better reflect the general population, allow longitudinal monitoring of individuals, and facilitate real-world experience sampling. We tested the feasibility of using a low-cost wearable headset to collect a relatively large EEG database (N = 230, 22-80 years old, 64.3% female), and an open-source automatic method to preprocess it. We then examined associations between well-being levels and the alpha center of gravity (CoG) as well as trait EEG asymmetries, in the frontal and temporoparietal (TP) areas. Robust linear regression models did not reveal an association between well-being and alpha (8-13 Hz) asymmetry in the frontal regions, nor with the CoG. However, well-being was associated with alpha asymmetry in the TP areas (i.e., corresponding to relatively less left than right TP cortical activity as well-being levels increased). This effect was driven by oscillatory activity in lower alpha frequencies (8-10.5 Hz), reinforcing the importance of dissociating sub-components of the alpha band when investigating alpha asymmetries. Age was correlated with both well-being and alpha asymmetry scores, but gender was not. Finally, EEG asymmetries in the other frequency bands were not associated with well-being, supporting the specific role of alpha asymmetries with the brain mechanisms underlying well-being levels. Interpretations, limitations, and recommendations for future studies are discussed. This paper presents novel methodological, experimental, and theoretical findings that help advance human neurophysiological monitoring techniques using wearable neurotechnologies and increase the feasibility of their implementation into real-world applications.

Transactional relations between maternal anxiety and toddler anxiety risk through toddler-solicited comforting behavior

INTRODUCTION

Transactional developmental and anxiety theories suggest that mothers and toddlers may influence each other's anxiety development across early childhood. Further, toddlers' successful solicitations of comfort during uncertain, yet manageable, situations, may be a behavioral mechanism by which mothers and toddlers impact each other over time. To test these ideas, the current study employed a longitudinal design to investigate bidirectional relations between maternal anxiety and toddler anxiety risk (observed inhibited temperament and mother-perceived anxiety, analyzed separately), through the mediating role of toddler-solicited maternal comforting behavior, across toddlerhood.

METHODS

Mothers (n = 174; 93.6% European American) and their toddlers (42.4% female; 83.7% European American) participated in laboratory assessments at child ages 1, 2, and 3 years. Mothers self-reported anxiety symptoms. Toddler anxiety risk was observed in the laboratory as inhibited temperament and reported by mothers. Solicited comforting interactions were observed across standardized laboratory tasks.

RESULTS

Direct and indirect bidirectional effects were tested simultaneously in two longitudinal path models. Toddler anxiety risk, but not maternal anxiety, predicted solicited comforting behavior, and solicited comforting behavior predicted maternal anxiety. No convincing evidence for parent-directed effects on toddler anxiety risk emerged.

CONCLUSION

Results support continued emphasis on child-elicited effects in child and parent anxiety development in early childhood.

Using different methods for calculating frontal alpha asymmetry to study its development from infancy to 3 years of age in a large longitudinal sample

Frontal electroencephalography (EEG) alpha asymmetry (FAA), defined as the difference in frontal alpha power observed over the right and left frontal scalp regions, has been widely used in developmental research as a measure of multiple aspects of child behavior, such as temperament. Studies have used different equations to calculate FAA, which renders comparison of results across studies challenging. Furthermore, few studies have examined FAA's longitudinal stability across infancy and early childhood, which is a desirable feature of a temperament measure. We investigated the cross-sectional and the longitudinal correlations of FAA values from four different equations to calculate FAA used in the literature. We used baseline EEG data from a longitudinal sample of 321 infants and 168 3-year-old children (149 of whom had data at both timepoints). Consistent with previous work, FAA values calculated using two commonly used equations were highly correlated with each other cross-sectionally but not with values from a different equation that used log-transformed relative power. The log-transformed relative power FAA values were the only values that showed significant longitudinal stability. These findings suggest that researchers interested in FAA as a trait-like measure in children should consider using the relative power equation that renders stability across ages.

Longitudinal investigation of shyness and physiological vulnerability: Moderating influences of attention biases to threat and safety

Shyness has long been identified as a vulnerability factor to developing psychosocial problems, but there is heterogeneity in these observed outcomes. One potential factor underlying these relations is individual differences in threat sensitivity. Using a longitudinal design, we examined whether attentional biases toward social threat and safety measured during adulthood moderated the association between shyness measured in emerging adulthood (N = 83, n_female = 48; M_age = 23.56 years, SD_age = 1.09 years) and frontal electroencephalogram (EEG) asymmetry at rest, a physiological index of vulnerability to psychopathology, measured nearly a decade later in adulthood (M_age = 31.68 years, SD_age = 2.27 years). We found that only biases to threat moderated the association between shyness and resting frontal EEG asymmetry longitudinally. In individuals who displayed relative vigilance to social threat, shyness was associated with greater relative right frontal EEG activity at rest (i.e., increased physiological vulnerability). These findings suggest that attentional biases to threat may play a role in understanding the relation between shyness and some known physiological vulnerabilities to psychopathology in adults.

Deriving within-person estimates of delta-beta coupling: A novel measure for identifying individual differences in emotion and neural function in childhood

Delta-beta coupling is increasingly used to understand early emotional development. However, little is known about the development of the coupling, limiting its utility for identifying normative or aberrant functioning. We used a prospective longitudinal sample (N = 122) to compare measures of within-person and between-person coupling between ages 3 and 5, track the developmental trajectory of coupling, identify individual differences in patterns of development, and explore emotion-related predictors and outcomes of discrete developmental patterns. Within-person measures, limited in overall utility, were most useful when (1) statistical approaches produced more homogenous groups within the overall sample (extreme groups or latent classes) or (2) the full developmental course was considered. We found two trajectories of change in frontal coupling and three trajectories of change in parietal coupling. Coupling trajectories were predicted by observed fear and approach/avoidance at age 3. In addition, high levels of frontal coupling at age 3 that declined and then levelled out through age 5 were associated with lower levels of internalizing by age 5. This work provides a foundation for understanding normative change in delta-beta coupling across the preschool years and useful insight for the use of this metric in future work.

Positive Shyness in the Brain: Frontal Electroencephalogram Alpha Asymmetry and Delta-Beta Correlation in Children

Positive shyness is thought to be an approach-dominant form of shyness, whereas non-positive shyness is thought to be an avoidance-dominant form of shyness. This study examined electrocortical and behavioral correlates of motivation and emotion in relation to these shy subtypes in 67 children (M_age  = 10.41 years, SD = 3.23). Using resting state electroencephalography, findings revealed that positive shy and low shy children had greater relative left frontal alpha asymmetry compared to non-positive shy children, and positive shy children had a higher frontal delta-beta correlation compared to other groups. Non-positive shy children scored highest on parent-reported school avoidance. These findings converge with previous work reporting distinct correlates in positive and non-positive shyness, extending this to two brain measures of motivation and emotion.

Positive and Negative Emotionality at Age 3 Predicts Change in Frontal EEG Asymmetry across Early Childhood

Depression is characterized by low positive emotionality (PE) and high negative emotionality (NE), as well as asymmetries in resting electroencephalography (EEG) alpha power. Moreover, frontal asymmetry has itself been linked to PE, NE, and related constructs. However, little is known about associations of temperamental PE and NE with resting EEG asymmetries in young children and whether this association changes as a function of development. In a longitudinal study of 254 three-year old children, we assessed PE and NE at age 3 using a standard laboratory observation procedure. Frontal EEG asymmetries were assessed at age 3 and three years later at age 6. We observed a significant three-way interaction of preschool PE and NE and age at assessment for asymmetry at F3-F4 electrode sites, such that children with both low PE and high NE developed a pattern of increasingly lower relative left-frontal cortical activity over time. In addition, F7-F8 asymmetry was predicted by a PE by time interaction, such that the frontal asymmetry in children with high PE virtually disappeared by age 6. Overall, these findings suggest that early temperament is associated with developmental changes in frontal asymmetry, and that the combination of low PE and high NE predicts the development of the pattern of frontal symmetry that is associated with depression.

Frontal brain maturation and the stability of children's shyness

Recent evidence suggests that relative to nonshy children, shy children exhibit a lower overall frontal EEG alpha/delta ratio (ADR) during middle childhood, possibly reflecting relatively less frontal brain maturation at this age. We examined this same ADR measure in relation to the stability of observed shyness and parent-reported child social anxiety measured across two laboratory visits separated by approximately 1 year during late childhood in 51 children (33% female, age range 10-16 years). We found that the overall frontal ADR score was significantly lower among children with high, stable observed shyness and parent-reported child social anxiety compared to children in the low, stable class. Findings provide convergent evidence suggesting that the stability of shyness in late childhood may be linked to relatively less overall frontal brain maturation at this age. We speculate on the adaptive function of delaying frontal brain maturation in the origins and maintenance of children's shyness.

Early childhood social reticence and neural response to peers in preadolescence predict social anxiety symptoms in midadolescence

BACKGROUND

Early childhood social reticence (SR) and preadolescent social anxiety (SA) symptoms increase the risk for more severe SA in later adolescence. Yet, not all at-risk youth develop more severe SA. The emergence of distinct patterns of neural response to socially evocative contexts during pivotal points in development may help explain this discontinuity. We tested the extent to which brain function during social interactions in preadolescence influenced the effects of SA and early childhood SR on predicting SA symptoms in midadolescence.

METHODS

Participants (N = 53) were assessed for SR from ages 2 to 7. At age 11, SA symptoms were assessed and brain function was measured using functional magnetic resonance imaging (fMRI) as participants anticipated social evaluation from purported peers with a reputation for being unpredictable, nice, and mean. At age 13, SA symptoms were re-assessed. Moderated-mediation models tested the extent to which early childhood SR, preadolescent SA, and preadolescent brain function predicted midadolescent SA.

RESULTS

In individuals with preadolescent SA, the presence of early childhood SR and SR-linked differences in brain activation predicted more severe SA in midadolescence. Specifically, in those who exhibited preadolescent SA, greater early childhood SR was associated with enhanced bilateral insula engagement while anticipating unpredictable-versus-nice social evaluation in preadolescence, and more severe SA in midadolescence.

CONCLUSIONS

SR-linked neural responses to socially evocative peer interactions may predict more severe SA symptoms in midadolescence among individuals with greater preadolescent SA symptoms and childhood SR. This same pattern of neural response may not be associated with more severe SA symptoms in youth with only one risk factor.

Mother-Child Interaction: Links Between Mother and Child Frontal Electroencephalograph Asymmetry and Negative Behavior

It is well accepted that parent-child interactions are bidirectional by nature, yet not much is known about the psychophysiological activity underlying these interactions. This study examined, during a parent-child interaction, how a child's negativity statistically predicted maternal frontal electroencephalograph (EEG) asymmetry and how a mother's negativity statistically predicted child frontal EEG asymmetry. Thirty-four mother-child dyads participated in the study. Maternal and child behaviors and physiology were measured during a puzzle task. Results indicated that mothers whose children exhibited more challenging behaviors during the dyadic interaction displayed more right (relative to left) asymmetry, as did children whose mothers were high in negativity during the interaction. These findings suggest that mothers and children react to each other's signals not only behaviorally but also physiologically.

Right frontal pole cortical thickness and executive functioning in children with traumatic brain injury: the impact on social problems

Cognitive and social outcomes may be negatively affected in children with a history of traumatic brain injury (TBI). We hypothesized that executive function would mediate the association between right frontal pole cortical thickness and problematic social behaviors. Child participants with a history of TBI were recruited from inpatient admissions for long-term follow-up (n = 23; average age = 12.8, average time post-injury =3.2 years). Three measures of executive function, the Trail Making Test, verbal fluency test, and the Conners' Continuous Performance Test-Second edition (CPT-II), were administered to each participant while caregivers completed the Childhood Behavior Checklist (CBCL). All participants underwent brain magnetic resonance imaging following cognitive testing. Regression analysis demonstrated right frontal pole cortical thickness significantly predicted social problems. Measures of executive functioning also significantly predicted social problems; however, the mediation model testing whether executive function mediated the relationship between cortical thickness and social problems was not statistically significant. Right frontal pole cortical thickness and omission errors on the CPT-II predicted Social Problems on the CBCL. Results did not indicate that the association between cortical thickness and social problems was mediated by executive function.

Stress correlates of hand preference in rhesus macaques

In this research we examined stress-related correlates of hand preference in monkeys. Specifically, we tested the hypothesis that stress reactivity and plasma levels of the stress hormone cortisol are developmentally related to handedness in rhesus macaques (Macaca mulatta). We found a significant positive correlation between cortisol levels sampled in juveniles and the frequency of right- versus left-hand use sampled in these same animals during adulthood. Right-hand preference was negatively correlated with stress reactivity. These data are consistent with the view that stress functioning and reactivity are associated with the development of hemispheric specialization in primates.